U.S. patent number 8,683,809 [Application Number 13/503,453] was granted by the patent office on 2014-04-01 for fossil-fueled power station comprising a carbon dioxide separation device and method for operating a fossil-fueled power station.
This patent grant is currently assigned to Siemens Aktiengesellschaft. The grantee listed for this patent is Ulrich Grumann, Ulrich Much, Andreas Pickard, Mike Rost. Invention is credited to Ulrich Grumann, Ulrich Much, Andreas Pickard, Mike Rost.
United States Patent |
8,683,809 |
Grumann , et al. |
April 1, 2014 |
Fossil-fueled power station comprising a carbon dioxide separation
device and method for operating a fossil-fueled power station
Abstract
A fossil-fueled power station including a steam generator is
provided. A steam turbine is mounted downstream of the steam
generator via a hot intermediate superheater line and a carbon
dioxide separation device. The carbon dioxide separation device is
connected to the hot intermediate superheater line via a process
steam line and a backpressure steam turbine is mounted into the
process steam line.
Inventors: |
Grumann; Ulrich (Erlangen,
DE), Much; Ulrich (Erlangen, DE), Pickard;
Andreas (Adelsdorf, DE), Rost; Mike (Erlangen,
DE) |
Applicant: |
Name |
City |
State |
Country |
Type |
Grumann; Ulrich
Much; Ulrich
Pickard; Andreas
Rost; Mike |
Erlangen
Erlangen
Adelsdorf
Erlangen |
N/A
N/A
N/A
N/A |
DE
DE
DE
DE |
|
|
Assignee: |
Siemens Aktiengesellschaft
(Munich, DE)
|
Family
ID: |
43840518 |
Appl.
No.: |
13/503,453 |
Filed: |
October 29, 2010 |
PCT
Filed: |
October 29, 2010 |
PCT No.: |
PCT/EP2010/066518 |
371(c)(1),(2),(4) Date: |
June 28, 2012 |
PCT
Pub. No.: |
WO2011/051473 |
PCT
Pub. Date: |
May 05, 2011 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
|
US 20120261922 A1 |
Oct 18, 2012 |
|
Foreign Application Priority Data
|
|
|
|
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Nov 2, 2009 [DE] |
|
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10 2009 051 640 |
|
Current U.S.
Class: |
60/772;
60/39.182; 60/39.5; 60/670 |
Current CPC
Class: |
F01K
7/22 (20130101); F01K 17/04 (20130101); F01K
23/10 (20130101); F01K 23/14 (20130101); Y02E
20/16 (20130101); Y02E 20/32 (20130101); Y02E
20/326 (20130101) |
Current International
Class: |
F02C
6/18 (20060101) |
Field of
Search: |
;60/39.182,39.5,772,775
;95/236 ;423/220-229 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1473072 |
|
Nov 2004 |
|
EP |
|
WO 2005045316 |
|
May 2005 |
|
WO |
|
WO 2011039263 |
|
Apr 2011 |
|
WO |
|
Primary Examiner: Sung; Gerald L
Assistant Examiner: Walthour; Scott
Claims
The invention claimed is:
1. A fossil-fueled power station, comprising: a steam generator; a
live steam line; a hot reheater line; a first steam turbine having
a high pressure stage connected to the steam generator via the live
steam line and having a medium- and low-pressure stage, the first
steam turbine also connected to the downstream side of the steam
generator via the hot reheater line; a cold reheater steam return
line extending from the first steam turbine to the steam generator;
a condenser connected downstream from the first steam turbine; a
carbon dioxide separation device comprising a heat exchanger, the
carbon dioxide separation device connected via a process steam line
to the hot reheater line of the steam generator; a condensate line
extending from the heat exchanger to the condenser; and a
back-pressure steam turbine, separate and distinct from the first
steam turbine, connected to the process steam line and positioned
between the hot reheater line and the carbon dioxide separation
device, a portion of the hot reheater line and the first steam
turbine extending along a first path to the condenser, with the
process steam line, the back-pressure steam turbine, the heat
exchanger and the condensate line extending along a second path to
the condenser parallel to the first path.
2. The fossil-fueled power station as claimed in claim 1, wherein
the back-pressure steam turbine is joined by a shaft to a generator
for the purpose of generating electricity.
3. The fossil-fueled power station as claimed in claim 1, wherein
the power station is in the form of a combined cycle gas turbine
power plant, incorporating a gas turbine, and wherein the steam
generator is a heat recovery steam generator.
4. A method for operating a fossil-fueled power station, with a
steam generator, comprising: connecting a first steam turbine
having a high pressure stage connected to the steam generator via a
live steam line, the first steam turbine further including a
medium- and low-pressure stage, the first steam turbine also
connected to the downstream side of the steam generator via a hot
reheater line; connecting a heat exchanger in a carbon dioxide
separation device to the hot reheater line of the steam generator
via a process steam line; extracting reheated steam from the hot
reheater line in the form of process steam; expanding the process
steam in an expansion process in a back-pressure steam turbine,
separate and distinct from the first steam turbine, wherein
expanded steam is formed; feeding the expanded steam to the carbon
dioxide separation device with the back-pressure steam turbine
connected to receive steam via a process steam line from the hot
reheater line, the back-pressure steam turbine positioned between
the hot reheater line and the carbon dioxide separation device; and
providing a condenser connected downstream from the first steam
turbine wherein a condensate line extends from the heat exchanger
to the condenser.
5. The method as claimed in claim 4, wherein the expansion process
also incorporates a generator, and is used for the generation of
electrical power.
6. The method as claimed in claim 4, wherein the expanded steam is
used for the desorption of carbon dioxide.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
This application is the US National Stage of International
Application No. PCT/EP2010/066518, filed Oct. 29, 2010 and claims
the benefit thereof. The International Application claims the
benefits of German application No. 10 2009 051 640.9 DE filed Nov.
2, 2009. All of the applications are incorporated by reference
herein in their entirety.
FIELD OF INVENTION
A fossil-fueled power station including a steam generator, a steam
turbine mounted downstream of the steam generator via a hot
intermediate superheater line and a carbon dioxide separation
device is provided. The carbon dioxide separation device is
connected to the hot intermediate superheater line via a process
steam line and a backpressure steam turbine is mounted into the
process steam line.
BACKGROUND OF INVENTION
The separation of carbon dioxide out of the exhaust gases from
fossil-fueled power stations, such as for example combined cycle
gas turbine (CCGT) power stations or coal-fired steam turbine power
stations, requires a large amount of energy.
If use is made of a wet-chemical absorption-desorption method for
the separation of carbon dioxide, this energy must be supplied in
the form of thermal energy for heating the desorption process.
Usually, low-pressure steam from the power station's steam circuit
is used for this purpose.
Even if a power station which is in the course of being built is
not yet equipped with a carbon dioxide separation device connected
into it, there is nowadays already an obligation to demonstrate
that it can be retrofitted (capture readiness). Accordingly,
appropriate provisions are nowadays already being made so that at a
later point in time a carbon dioxide separation device can be
integrated into the power station without any problems. This type
of provision also affects, for example, the machine housing, which
must be appropriately enlarged for the extraction of the low
pressure steam.
In addition, there is a requirement that the steam turbine, or the
power station process, must be appropriately configured for the
extraction of low pressure steam. In the case of steam turbines
with separate housings for the medium- and low-pressure stages, the
extraction of low pressure steam at the overflow line is an easy
possibility. On the other hand, in the case of steam turbines with
a single-housing medium- and low-pressure stage, it is not possible
to extract the required large quantity of steam from the turbine at
a suitable pressure.
The extraction of steam from other sources within the power station
process is often not to be recommended, or is not possible in a
suitable way. Thus, for example, extraction from a reheater line on
the steam turbine produces an unbalanced load on the boiler.
Extraction of higher grade steam for the carbon dioxide separation
device must also be excluded, because this leads to unacceptable
energy losses.
SUMMARY OF INVENTION
It is therefore the object of the invention to specify a device and
a method for a fossil-fueled power station, for providing low
pressure steam for a carbon dioxide separation device from a source
other than the overflow line between the medium- and low-pressure
stages, so that an unbalanced load in the power station process is
avoided and the energy losses due to the extraction of the steam
are largely minimized.
That object of the invention which relates to a device is achieved
by the characteristics of the claims.
The invention starts with a steam turbine which has a
single-housing medium- and low-pressure stage. Apart from the
medium- and low-pressure stages, the steam turbine also
incorporates a high pressure stage in a separate housing. In this
case, provision is made so that, after it emerges from the high
pressure stage, the live steam for the high pressure stage is fed
back via a steam return line (cold reheater line) into the boiler
for reheating, is reheated and is fed into the medium pressure
stage of the steam turbine via a hot reheater line. In accordance
with the invention, provision is now made so that a process steam
line, which is connected to the carbon dioxide separation device,
is connected to the hot reheater line with a back-pressure steam
turbine being connected into the process steam line. The
back-pressure steam turbine brings the process steam which has been
extracted to the condition for process steam (saturated steam). The
boiler must be appropriately designed for the extraction of the
steam.
In an advantageous development of the fossil-fueled power station,
the process steam which has been extracted is converted to
electrical power by a generator connected to the back-pressure
steam turbine. By this means, the excess energy in the process
steam can be used for the generation of electrical power.
In an expedient embodiment of the fossil-fueled power station, the
carbon dioxide separation process consists of an absorption unit
and a desorption unit. The process steam line is then connected to
the input side on a heat exchanger in the desorption unit. On the
output side, the desorption unit is connected to a condensate
return line.
That object of the invention which relates to a method is achieved
by the characteristics of the claims.
In an analogous way as with the device, in the case of the
inventive method the process steam is extracted from the hot
reheater line. The process steam is in this case expanded in an
expansion process, which produces expanded steam (saturated steam).
The expanded steam is then fed to the carbon dioxide separation
device.
It is advantageous if the expansion process is used for the
generation of electrical power. The expanded steam is preferably
used for the desorption of carbon dioxide in a carbon dioxide
separation process.
The preparatory measures for "capture ready" are reduced by the
invention to an appropriate boiler design and a connection point
outside the system-critical machine housing. When a carbon dioxide
separation device is retrofitted, the steam turbine can be
thermodynamically optimized for the separation process then used.
The connection of the back-pressure turbine before the reheater
leads to lower temperature steam, which can be expanded with no
problem using standard industrial turbines.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in more detail below by reference to a
drawing.
DETAILED DESCRIPTION OF INVENTION
The figure shows the essentials of a fossil-fueled power station 1
with a heat exchanger 21 connected to a carbon dioxide separation
device 5. The fossil-fueled power station 1 is here in the form of
a combined cycle gas turbine (CCGT) power plant 12. The combined
cycle gas turbine plant 12 is shown in simplified form, and here
consists of a gas turbine 13, a steam turbine 2, a generator 20,
and a steam generator 4 connected in the exhaust gas duct of the
gas turbine, in the form of a heat recovery steam generator 15.The
steam turbine 2 consists of a high pressure stage 24 and a medium-
and low-pressure stage 25. The gas turbine 13, the generator 20 and
the steam turbine 2 are located on a common shaft 8. Connected
downstream from the steam turbine 2 is a condenser 22.
The high pressure stage 24 has a live steam feed connection from
the steam generator 4 via a live steam line 23 and a steam return
feed connection via a steam return line (cold reheater line) 3.
Connected to the steam generator 4 there is also a hot reheater
line 16, which is connected to the medium- and low-pressure part 25
of the steam turbine 2.
Connected to the hot reheater line 16 is a process steam line 6 for
tapping off process steam 17. In addition to the steam turbine 2, a
back-pressure steam turbine 7 is provided, this having a process
steam feed connection from the process steam line 6. Expansion of
the process steam 17 takes place in the back-pressure steam turbine
7, to form saturated steam 26. In the course of this, the process
steam 17 is converted to electrical power by a generator 9
connected to the back-pressure steam turbine 7. When the steam is
extracted from the hot reheater line, its temperature on exiting
from the back-pressure steam turbine is about 290.degree. C.
Connected to the back-pressure steam turbine 7 is a heat exchanger
21 in a carbon dioxide separation device 5. Here, the carbon
dioxide separation device 5 is not shown in more detail. The
back-pressure steam turbine 7 is connected to the desorption unit
of the carbon dioxide separation device 5 via a saturated steam
line 28. In the desorption unit, the saturated steam 26 promotes
the boiling off of a solvent to release carbon dioxide.
From the heat exchanger 21, a condensate is fed out into the
condenser 22 via a condensate return line 29. For this purpose, the
condensate return line 29 has an appropriate connection to the
condenser 22. Finally, a condensate line 30 is provided, connecting
the condenser 22 to the steam generator 4, to close the feedwater
circuit.
* * * * *